1. Technical Field
The present invention is directed to an improved data processing system and, in particular, an improved mechanism for detecting and correcting inaccuracies in curve fit models.
2. Description of Related Art
With simulation and empirical data, it is often beneficial to estimate the values of data at points not included in the actual simulation and empirical data, i.e. to extrapolate the data. In order to obtain an estimate of data at points not already known or determined, often curve fitting to the known data points is performed.
Curve fitting involves a number of steps to obtain the best curve fit to a particular set of data. First, a curve equation must be selected. Then, the coefficients for that equation must be determined. Thereafter, the equation using the current coefficients is tested against the simulation data or empirical data to see how well the equation represents the data at the actual simulation or empirical data points. The coefficients are then changed to improve the fit of the curve to the actual simulation or empirical data points. This process is then iterated until an acceptable fit is achieved.
The equation of a straight line is simple but normally does not match simulation or empirical data well. A higher order polynomial equation can make more twists and turns through the data points and therefore, makes a better fit to the actual simulation or empirical data points.
These higher order polynomials match well at the actual simulation or empirical data points, but may have large oscillations between the actual data points thereby generating humps or dips. These humps and dips do not generally occur in the actual simulation or empirical data and therefore, the humps and dips represent inaccuracies in the modeling of the simulation or empirical data even though the curve fits the actual simulation or empirical data. Therefore, it would be beneficial to have a method and apparatus for identifying these humps and dips and improving the modeling of the actual simulation or empirical data.